The Texas State Board of Education is expected to take the final vote on its contentious social studies curriculum on Friday.

After 18 months of work, the board is nearing the vote that could revise the state’s social studies curriculum to put more emphasis on religion and the role of Christianity in the founding of America.

Since Texas is the second-largest textbook market in the country, the curriculum it approves is expected to influence publishers and thus the textbooks used in classrooms nationwide.

“[E]ducators, experts, parents and members of the business community are sending a message: we don’t want the American Atheists and the ACLU in charge of writing our history standards and we don’t want a delay of the final vote,” said Jonathan Saenz, director of legislative affairs for Liberty Institute. “Liberal fringe efforts to complicate, obfuscate, and denigrate our heritage and history must be rejected. A vote delayed is a vote denied.”

The vote has already been delayed once before and critics are calling for another delay in the vote.

Opponents of the proposed new textbook guidelines say the revision is a vehicle to promote a political ideology. They noted that the proposal included highlighting that Republicans were overwhelmingly in favor of ending slavery, whereas Southern Democrats were against the change. It also called for including history about the Black Panther, an aggressive African-American organization that defended the rights of black people. Supporters of the change say the history of the Black Panther is needed to tell the full story and to contrast it with the peaceful activism of Dr. Martin Luther King, Jr.

“We have allowed ideology to drive and define the standards of our Texas Curriculum and it has swung from liberal to conservative depending on the members of state board,” said Rod Paige, former U.S. Education Secretary under President George W. Bush on Wednesday, according to the National Association for the Advancement of Colored People. “What students are taught should not be the handmaiden of political ideology."

More than 200 people listed their names to testify Wednesday before the state’s board of education.

Changes to the proposed curriculum are expected to be debated Thursday.